隧道结构对高速列车穿行过程气动特性的影响

以CRH2型高速列车穿行隧道过程的气动特性为研究对象,建立了列车模型及具有不同缓冲结构、不同阻塞比的隧道计算模型,并与相同工况下的模型实验进行对比,验证了仿真模型的可行性.以kε-湍流模型为基础,对高速列车以不同速度进入具有不同缓冲结构、不同阻塞比的隧道时的外流场进行了仿真模拟.分析了列车在进入隧道时压缩波的产生机理,得到了列车表面风口在车体进入隧道过程中的压力波动情况.仿真结果表明：隧道缓冲结构的缓冲性能按抛物线型、线性、不连续性的顺序依次减小;压力值随阻塞比增大而线性减小.由此提出了减小列车进入隧道时表面压力波动的方法.

Influence of tunnel structure to aerodynamic behaviors of a high-speed train passing through

The train model and tunnel models with various buffer structures and blockage ratios were built to investigate aerodynamic behaviors of a CRH2 high-speed train. The above models were tested by comparing the experimental results under the same work conditions which were described and submitted in the literature. Based on the k-ε turbulent model, the flow of air field out the train was simu- lated under different conditions： the train passed tunnel with various buffer structures and blockage ra- tios at different speeds. The mechanism of pressure wave production and fluctuation of the wind vents on vehicles were analyzed, and the simulation results show that the buffer capacity of the parabolic, linear and discontinuous buffer structure decrease in turn, the pressure becomes greater as the blockage ratio increases. Also the method of decreasing pressure fluctuation is obtained.